Over the last several decades significant strides have been made in the development of increasingly automated clinical diagnostic equipment. Initially, the domain of manual laboratory procedures, new diagnostic procedures have been developed for point of care testing requiring little or no equipment, e.g., the Siemens Medical Solutions Diagnostics DCA 2000® HbAlc immunoassay cartridge, for low throughput benchtop analyzers, e.g., Roche Diagnostics” Cobas® c 311 chemistry analyzer, and for high throughput mainframe clinical chemistry analyzers, e.g., Ortho Clinical Diagnostics 5600® analyzer.
Irrespective of the throughput rate of the analyzer, one trend in modern clinical diagnostic analysis is the use of smaller and smaller sample sizes in the diagnostic equipment. Whereas, e.g., in the analysis of blood, once sample sizes in the range of milliliters were required, now in many cases sample sizes in the range of microliters is all that is necessary. The advantage to patients and personnel conducting the sample collection and analysis is significant in that the sample blood draw can often be reduced from a venipuncture (usually collecting about 8.5 mL of blood per tube, up to 3 tubes) to a finger stick (usually collecting about 35 μL of blood); a finger stick also has the potential to minimize the exposure of laboratory personnel to infectious agents and to minimize the potential for hazardous spills. The disadvantage to personnel conducting the sample collection and analysis is the dexterity required to handle and manipulate μL quantities of sample especially when the initial sample is collected via venipuncture.